Giardia

1. World wide disease • First appeared in Oregon in 1988 • Looks like a smiley face Giardia Presented by Jennifer Sierra and Florinda Paz

2. Histology of the Etiologic Agent • 1681, Antoine van Leeuwenhoek, first discovered Giardia lamblia in his own stool • Fact: At first, G. lamblia was considered to be of doubtful pathogenicity • 1859, Vilém Dušan Lambl rediscovered the parasite in stool of pediatric patients in Prague. Lambl published a full description of the parasite and included drawings • 1915, Giardia was described by Fantham and Porter when veterans returning from war contracted the disease and the human stool isolates produced diarrhea in kittens • 1954, Rendtorff established that cysts could be transmitted by water source by feeding prisoners Giardia cysts from asymptomatic human donors • 1970, awareness of the parasite increased when visitors from the Soviet Union returned with symptomatic Giardiasis

3. Example of a case in Giardia • Hillary, age 6, and her sister Debbie, age 7, went to a petting zoo at their local fair. While they were there they pet a few goats. (animal-person transmission). • Hillary, was acting normal and being herself for a few days • A week later (incubation time), after they went to the petting zoo Hillary started to feel uneasiness in the intestine followed by nausea. Two days later she had abdominal pain, and explosive diarrhea (acute stage and symptoms). • Hillary’s parents took her to the doctor. She had her stool examined and tested positive for Giardia. • To treat the disease, Hillary was given Tinidazole (50mg/kg) to help against the cyst stage of Giardia • Cysts were cleared about 12 days later

4. How Giardia Is Transmitted Photo Credit: Courtesy of CDC/Alexander J. da Silva/Melanie Moser

5. Virulence Factors Giardia lamblia is a parasite that feeds of an organism to survive. The organism is microscopic • It is also known as Giardia intestinalis, Giardia lamblia, or Giardia duodenalis • Cysts are 7-10um in length and are oval shaped. • 4 Pairs of flagella • Organelle’s arrangement makes it look like a smiley face • Has suction like cup mouth it uses to stick to the intestinal wall • A mature cyst contains nuclei. The cyst is environmentally resistant and responsible for disease transmission. • Inoculation dose is 10 to 100 cyst The life cycle of the parasite has two stages: cyst and trophozoite • When a cyst is ingested, it marks the beginning of the life cycle • CONT. NEXT PAGE

6. Virulence Factors (Cont.) • Once cyst is ingested, the mature cysts in the small intestine release trophozoites through a process called excystation. • Cysts are able to survive exposure to gastric acid, gastric acid may also trigger excystation • Cyst attaches with a an adhesive disc to the intestinal wall and remains there until excreted along with feces • Once attached to intestinal wall it alters the mucous • The trophozoites stage is responsible for producing clinical disease in humans • Trophozoites have two nuclei and have four pairs of flagella. • The trophozoites look like teardrops when viewed from the top and are spoon shaped from the side. • Trophozoites colonize in the small intestine by attaching to the mucosa of the bowel using a ventral sucking disks. Then they multiply by binary fission • As the Giardia trophozoites move toward the colon, they retreat into the cyst stage and the new cysts are excreted in the feces.

7. Source: www.bip.am.lublin.pl/protozoa_id_8149.html

8. Pathophysiology • Giardia is not completely understood due to the great variation seen in the disease expression • Clinical presentation is seen from asymptomatic cyst passage to chronic diarrhea • Histologic exams of the duodenum show minimal or no abnormal representations • The intestinal mucosa may be damaged by the trophozoite itself disrupting the epithelial brush border during attachment. Also toxic substances from the organism itself may damage the intestinal epithelium.

9. Pathophysiolgoy (Cont.) • Bile salts in the duodenum may be taken up by the trophozoites, triggering encystation and stimulating parasite growth • Disease lives on glucose, vitamin B, and bile salts inside the body • Incubation time is usually one to four weeks • Children in daycares, campers, and hikers are at higher risk for Giardia • Disease will not spread from the intestine to other parts of the body

10. Symptoms • Some people may not develop symptoms but are still carriers of the parasite • Watery, foul-smelling diarrhea • Greasy pale loose stool (the greasy look is from the intestinal wall mucous • Fatigue • Fever and vomiting are rare • Abdominal cramps/ bloating • Belching gas • Nausea • Weight loss • Symptoms may last 2-4 weeks • You should visit a doctor if you become dehydrated or have traveled to areas where Giardia infection is present, or you have consumed water from a lake or stream

11. Mode of Transmission • Giardia parasites live in the intestines of people and animals • Before they pass in stool, they are encased in hard shells called cysts, allowing them to survive outside the intestine for months • Once inside a host, the cysts dissolve and the parasites are released • You can ingest the parasite by drinking contaminated water, eating contaminated food or person-to person contact

12. Mode of Transmission (Cont.) Swallowing contaminated water Giardia parasites are found in lakes, ponds, rivers, and worldwide streams. They are also found in swimming pools contaminated by children in diapers and in improperly treated water Eating contaminated food: Taking food that was handled by a person who didn’t wash their hands or used contaminated water to wash hands Person to person: Hands become contaminated with fecal matter like parents changing diapers or shake hands with infected person

13. Diagnosis • Multiple stool collections are used to test sensitivity

14. Prevention • Prevention: Good hygiene, wash hands, avoid contact with feces of an infected person/animal, and drink bottled water when traveling • Avoid swallowing water in swimming pools and spas, if you have diarrhea try not to go in public water • Minimize contact with feces of animals

15. Treatment • Drugs like metroindazole, tinidazole, and nitazoxanide can be taken • Be sure to discuss treatment options with a health care provider because drugs may be have an effect on medical history and condition of immune system • Tinidazole has demonstrated activity against the cyst stage • Nitazoxanide relieves symptoms and is easier for children to take because it comes in liquid form

16. Giardia cases in the U.S. • From 1998-2002, the total number of cases reported for Giardia decreased from 24,226 in 1998 to 19,708 in 2001. It then increased to 21,300 in 2002 • There was a greater report in children ages 1-9 and for adults 30-39 years compared with other age groups • Giardiasis reports was higher in northern states and was at peak during early summer through early fall • The increase in disease observed in cases in 2002 may be due to an increase of parasites in lakes, rivers, or swimming pools

17. Giardia Cases in Oregon • Between the years of 2000-2009 Oregon had 9.3-12.5 ( Rate per 100,00) reported cases of Giardia in Marion County • In 2009, Oregon had nearly twice the reported cases of Giardia than the rest of the United States

18. Importance of Disease • It is important to study this disease so we know how to treat it • The disease can be very easily transmitted but it can also be easily prevented • We need to study the disease to have a better understanding of what it does in the body

19. References • "Epidemiology & Risk Factors." Centers for Disease Control and Prevention. Centers for Disease Control and Prevention, 13 July 2012. Web. 14 July 2013. <http://www.cdc.gov/parasites/giardia/epi.html>. This page will give you information on how to prevent becoming infected with Giardia disease. •  "The Giardia Lamblia Organism." The Giardia Lamblia (instinalis) Parasite. N.p., n.d. Web. 14 July 2013. <http://www.giardiasis.org/Giardia-Lamblia.aspx>. Here you can find information about the disease’s shape, size and structure and how it becomes pathogenic • Giardiasis. 2010. Photograph. Http://www.CDC.gov/parasites/giardia/biology.html, n.p. Photograph used on slide 4 • Giardiasis. Salem: Public Health, 2009. Print. The pamphlet will give you information on Giardia in Oregon along with symptoms and transmission of disease. • "History of Giardia." Discovery and History of Giardia. N.p., n.d. Web. 13 July 2013. <http://www.giardiasis.org/History.aspx>. Here you can find information on Giardia’s history and how it was discovered

20. References • Mayo Clinic Staff. "Giardia Infection (giardiasis)." Mayo Clinic. Mayo Foundation for Medical Education and Research, 14 Nov. 2012. Web. 11 July 2013. <http://www.mayoclinic.com/health/giardia-infection/DS00739/DSECTION=symptoms>. Here you will find symptoms related to disease and when you should see a doctor •  Mayo Clinic Staff. "Giardia Infection (giardiasis)." Mayo Clinic. Mayo Foundation for Medical Education and Research, 14 Nov. 2012. Web. 12 July 2013. <http://www.mayoclinic.com/health/giardia-infection/DS00739/DSECTION=causes>. This website will give you information on what causes Giardia and examples of the mode of transmission • Mayo Clinic Staff. "Giardia Infection (giardiasis): Treatment and Drugs." Mayo Clinic. Mayo Foundation for Medical Education and Research, 14 Nov. 2012. Web. 13 July 2013. <http://www.mayoclinic.com/health/giardia-infection/DS00739/ DSECTION=treatments-and-drugs>. This page tell you what drugs you can take to help treat the disease .

21. References •  "Prevention of Giardiasis." Preventing Giardiasis. N.p., n.d. Web. 13 July 2013. <http://www.giardiasis.org/Prevention.aspx>. Here you can find information on what you can do everyday to prevent the infection of Giardia • "Symptoms of Giardiasis." Symptoms of Giardia Infection. N.p., n.d. Web. 12 July 2013. <http://www.giardiasis.org/Symptoms.aspx> This website will give you information on what causes Giardia and who is most likely to become infected and where you can acquire the disease